BB Rotation

[ThunderCactus]

I think the endeavor is to simply understand the actual physics lol

[krap101]

Originally Posted by ThunderCactus

I think the endeavor is to simply understand the actual physics lol

I thought that this was the first step to becoming a wizard. If you know of an easier way... :P

[Blackthorne]

Originally Posted by krap101

I've gotten into a bit of a scuffle at ASM over bb dynamics theories, but lack the raw data to support my theory and/or create a new one.

Same here and I am tired of no one having anything to base their arguments on.

Originally Posted by krap101

Are you planning on releasing the data?

Yes, we are going to publish along side the MSED project we are hosting for Nathan.

Originally Posted by krap101

RiotSC over at ASM has conducted a similar test, but I'll get back to you on the results.

Good. PM a link to that thread. The more people that do this kind of testing means more data, but we should all be "kinda" doing it the same way. Maybe I can learn from their mistakes when we build our rig.

Originally Posted by Dynamo

ok.. this is really easy to do with a highspeed camera..it just takes some planning. take a BB, draw a line around or even just take a sharpie and color one whole hemisphere in black. take a piece of cardboard and draw some vertical lines with 1inch spacing. take the BB and manually place it in the opening of the hop chamber so that the line/hemisphere is lined up horizontally. then proceed to shoot the BB past the lined cardboard and film it. when looking at the film, you can track the BB as it passes over the lined cardboard and count how many lines it passes for every frame, as well as count the number of revolutions the BB makes. no need to calculate acceleration from the hopup down the barrel, as the BB will start to decelerate the moment is leaves the end of the barrel.

You missed Kraps post on frame rate being a factor in this. It factors in a huge amount. Especially if you are shooting on prism based film camera and not digital (we will be filming on both)

[krap101]

Anyways, after looking at some of the video that I took, I realized that I didn't take into account distance from the camera or the velocity (angular rates). At 1000fps, I got around 3 frames of footage of the bb, most of which was a white blur. Next weekend I'll try keeping the camera further away to give it a little more time, and also have a tripod...

[surebet]

This thread is giving me a boner. Any chance of public footage on these tests from any of you guys?

[krap101]

Originally Posted by surebet

This thread is giving me a boner. Any chance of public footage on these tests from any of you guys?

interesting image... I can post the normal stuff, but the high speed footage is just fugly. I had to go through the entire thing four times to find one shot (out of like 10), and that was totally useless.

So far this is the stuff I've edited/uploaded (from last week)

Beta 1 test 10 9 11 - YouTube


this one is a bit hard on the eyes... it's black/white and zoomed version of the first one.
Test Split short muted - YouTube

Might not have been what you were looking for :P


Evidence of the hs failure






Inverted

[coach]

Are you filming this outside with a car window as the backdrop? Sheesh! At the least, you need a solid contrasting colour!

[krap101]

Originally Posted by coachster

Are you filming this outside with a car window as the backdrop? Sheesh! At the least, you need a solid contrasting colour!

Yeah, the problem with high speed is normally artificial lighting isn't sufficient (as someone "less than an amateur"), so it must be outside (and today was cloudy). I'm not particularly equipped for this, and didn't have a tripod available, so I had to use my car to keep it steady. If I had enough light I would definitely do this indoors with a solid backdrop, no wind, i.e. perfect conditions, and also with the camera further back to give the it a chance.

The bigger problem was that the camera was too close and had only have 2-3 thousandths of a second to catch the bb going by. This was just a test to see what things needed to be changed in the future, although I did expect it to go better. Once I go home, I'll have a much better setup, and a bit more time to set everything up.